1. Field
This invention relates to improvements in the method of securing medical transducers to a patient's arm.
2. Prior Art
In the treatment of a patient, it is often important to monitor the patient's condition by means of a transducer. Typically the transducer is connected to the patient by way of a catheter and needle. For a transducer to operate properly, it generally must be maintained at some level, such as at the level of the patient's heart. The lower arm is often a suitable location for a transducer because the patient is normally careful to keep his lower arm at his side when a needle is inserted in the upper arm. This maintains the lower arm at the correct level with respect to the heart and the catheter length is short, extending only from the upper arm to the lower arm. Short catheter lengths are desired to facilitate patient care because they are easily kept out of the way.
There are two principal prior art methods of mounting a transducer. In the first, the transducer is simply secured to the patient's arm with gauze. In the second the transducer is supported at the desired level on a pole, some distance from the bed.
There are a number of problems with both of these methods. In the first, the transducer tends to twist as the patient moves. This in turn can cause the needle to twist in the patient's arm and can often result in severe pain.
In the second, a catheter 6 to 8 feet long is required to connect the transducer to the patient. The catheter is often curled across the top of the patient, encumbering nurses in caring for the patient. In addition, the transducer position must be changed each time the bed is raised or lowered to maintain it at the proper level and the probability of air entrapment is relatively high with the long catheter.
In either of these two methods, the setup time is long, the chance of obtaining an erroneous reading is relatively high, and the resulting arrngement is, at best, awkward.